The subject matter of the present invention relates generally to cyclone separator apparatus and method of manufacture for such apparatus. In particular, the invention relates to cyclone separator cone apparatus and method of making including a cone of abrasion resistant material which is bonded to a cover sleeve of plastic material that is provided with a plurality of flexible seal regions The flexible seal regions include circular ridge projections on the outer surface of the seal regions, at least some of such seal regions being spaced away from the outer surface of the cone for greater flexibility.
The separator cone apparatus of the present invention may be used to separate heavy fraction material and light fraction material from any liquid, but is especially useful for cleaning foreign matter including solid particles and heavy fraction reject material from a paper pulp slurry. The present invention enables such separator cones to be sealed in apertures provided through the walls of at least three separate pressure chambers even though such apertures are not in exact axial aligment, and the cones are out of round and not exactly symmetrical so that the seal regions are not in perfect alignment. Each cone has an inlet for tangentially injecting stock liquid into the cone from a liquid stock supply chamber of high pressure. A heavy fraction outlet is provided at the small end of the cone normally from a reject chamber of intermediate pressure, and a light fraction outlet is provided at the large end of the cone normally connected to an accept chamber of lower pressure. A water supply chamber may also be connected to a water inlet adjacent the small end of the cone between the stock chamber and the reject chamber, for thinning thickened stock. This frees acceptable fiber from rejects and prevents eccessive stock loss.
As shown in U.S. Pat. No. 3,486,618 of Wikdahl issued Dec. 20, 1969 and U.S. Pat. No. 3,959,123 of Wikdahl issued May 25, 1976, it is old to provide a canister type of hydrocyclone separator unit with a plurality of rows of cyclone cleaner cones which are mounted by seals in apertures provided through the walls of pressure chambers. Previously, it has been conventional to provide resilient rubber gaskets around the cone to form the seals between the cleaner cone and the pressure chamber walls. While such rubber gasket seals can be compressed, they cannot move laterally sufficiently to seal a non-symmetrical cone and/or non-aligned mounting apertures in the pressure chamber walls. Thus, sometimes the cone is made out of round or non-symmetrical and the mounting apertures are not concentric but are laterally offset from the axis of the cone, which presents a difficult sealing problem. In order to attempt to accommodate some axial misalignment of the apertures or non-symmetry of the cone, the sealing gaskets are sometimes made large enough to cover a small amount of lateral offset of the aperture relative to the cone axis. However, the sealing gasket seal must be soft enough to compress sufficiently to seal the small axially misalignment of a mounting aperture without resulting in too great a pressure which might break the cleaner cone when it is made of ceramic material. Of course, any seal must be sufficiently strong to withstand the pressure encountered in the chambers which are coupled to the inlet and outlets of the cone. Therefore, such rubber gaskets frequently cannot form adequate seals when there is any appreciable axial misalignment of the mounting apertures or non-symmetry of the cone.
U.S. Pat. No. 3,800,946 of Reid et al issued Apr. 2, 1974 shows a hydrocyclone including cyclone cleaner cones made of polyurethane plastic material which is provided with sealing ridges formed integral with the outer surface of such cleaning cone. However, such plastic cleaning cone is of great thickness to withstand the pressure of the liquid cyclone produced within the cone so that the seals provided on its outer surface are not flexible. This prevents sealing when the apertures in the support walls are not in alignment or the cone is not symmetrical about its axis. In addition, the cone wears out relatively quickly due to abrasion compared to the long useful life of a ceramic cone. These problems are avoided in the present invention by providing a thin plastic cover sleeve with flexible seal regions covering the outer surface of a cleaner cone of abrasion resistant material, such as ceramic, which is harder than the sleeve and is of a higher melting temperature.
U.S. Pat. No. 3,747,306 of Wikdahl issued July 24, 1973 shows cyclone cleaner cones made of ceramic material. However, there is no cover sleeve of plastic material bonded to the outer surface of such cone. Also, there is no plastic cover sleeve provided with flexible seal regions spaced from the outer surface of the cone and including sealing ridges formed on the outer surface of such sealing regions in the manner of the present invention. Instead, the ceramic cone member is provided with ridges on its outer surface which apparently forms a seal with a surrounding resilient sealing member such as a rubber gasket between the cone and the mounting apertures in the pressure chamber walls.
U.S. Pat. No. 4,053,393 of Day et al issued Oct. 11, 1977 shows a cyclone cleaner cone apparatus having a composite cone including a ceramic cone portion joined by interengaging projections to an elastomer cone portion made of polyurethane or other suitable plastic material, such composite cone being covered by a housing apparently made of metal. In one embodiment, the ceramic cone portion is inserted within an elastomer sleeve or liner which also forms the plastic cone portion. However, such sleeve is not provided with any sealing regions much less flexible sealing regions including annular projections or ridges in the manner of the present invention at least some of which are spaced from the outer surface of the ceramic cone. Indeed, a metal housing surrounds the composite cone and sleeve which apparently precludes any seals from being formed between flexible seal regions on the sleeve and a surrounding mounting wall aperture in the manner of the present invention.